If the server only supports higher TLS version like TLS 1.2 only, it will still fail unless your client PC is configured to use higher TLS version by default. To overcome this problem, add the following in your code: System.Net.ServicePointManager.SecurityProtocol |= SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls; Modifying your code example, it would be HttpClient httpClient … Read more
You are misusing the API. Here’s the situation: in ASP.NET, only one thread can handle a request at a time. You can do some parallel processing if necessary (borrowing additional threads from the thread pool), but only one thread would have the request context (the additional threads do not have the request context). This is … Read more
using System; using System.Collections.Generic; using System.Net.Http; class Program { static void Main(string[] args) { Task.Run(() => MainAsync()); Console.ReadLine(); } static async Task MainAsync() { using (var client = new HttpClient()) { client.BaseAddress = new Uri(“http://localhost:6740”); var content = new FormUrlEncodedContent(new[] { new KeyValuePair<string, string>(“”, “login”) }); var result = await client.PostAsync(“/api/Membership/exists”, content); string resultContent = … Read more
HttpClient is the newer of the APIs and it has the benefits of has a good async programming model being worked on by Henrik F Nielson who is basically one of the inventors of HTTP, and he designed the API so it is easy for you to follow the HTTP standard, e.g. generating standards-compliant headers … Read more
HttpClient has been designed to be re-used for multiple calls. Even across multiple threads. The HttpClientHandler has Credentials and Cookies that are intended to be re-used across calls. Having a new HttpClient instance requires re-setting up all of that stuff. Also, the DefaultRequestHeaders property contains properties that are intended for multiple calls. Having to reset … Read more
my result looks like this: public static async Task<string> Upload(byte[] image) { using (var client = new HttpClient()) { using (var content = new MultipartFormDataContent(“Upload—-” + DateTime.Now.ToString(CultureInfo.InvariantCulture))) { content.Add(new StreamContent(new MemoryStream(image)), “bilddatei”, “upload.jpg”); using ( var message = await client.PostAsync(“http://www.directupload.net/index.php?mode=upload”, content)) { var input = await message.Content.ReadAsStringAsync(); return !string.IsNullOrWhiteSpace(input) ? Regex.Match(input, @”http://\w*\.directupload\.net/images/\d*/\w*\.[a-z]{3}”).Value : null; } … Read more
The content type is a header of the content, not of the request, which is why this is failing. AddWithoutValidation as suggested by Robert Levy may work, but you can also set the content type when creating the request content itself (note that the code snippet adds application/json in two places-for Accept and Content-Type headers): … Read more
The general consensus is that you do not (should not) need to dispose of HttpClient. Many people who are intimately involved in the way it works have stated this. See Darrel Miller’s blog post and a related SO post: HttpClient crawling results in memory leak for reference. I’d also strongly suggest that you read the … Read more